Vaporization provides a desirable alternative to combustion for the delivery and consumption of botanical substances. Because vaporization can aerosolize components of botanical substances at a lower temperature than combustion, there is less heat-related degradation of the substances. Furthermore, vaporization avoids the generation of the noxious secondary compounds typically formed by direct combustion, providing obvious health benefits.
As will be appreciated, a vaporizer requires a suitable heat source to generate the necessary heat. For many applications, combustion of a fuel is a practical source of this heat. Combustible fuels allow for easy portability, given their relatively high energy density, and represent a quick and efficient heat source. Other sources of heat, such as electric resistance, require either access to household current or a relatively unwieldy battery to provide the necessary power, and can suffer from slow heating times. Thus, in light of the advantages noted above, a number of attempts have been made to implement vaporizing techniques for the consumption of botanical substances using a combustible fuel source.
For example, U.S. Pat. No. 7,434,584 to Steinberg (2008) describes a vaporizer that uses a butane flame to heat botanicals to a vaporizing temperature. However, the inhalation air and the combustion air are not kept separate, causing the user to be exposed to the combustion byproducts. As such, this device sacrifices one of the significant benefits of employing a vaporizer.
U.S. Pat. No. 5,060,667 to Strubel, on the other hand, is directed to a smoking article that separates the combustion byproducts from the inhalation air. Strubel's design mimics the conventional shape of a cigarette and discloses that the combustion fuel be internal to the device, arranged inside a cylindrical heat exchanger. With no practical means for refueling such a device, it is limited to a single use. Furthermore, the fuel must burn along the axis of the cylindrical device, concentrating the generated heat at different locations during the process. In turn, this creates an uneven temperature profile and offers little control over maintaining the correct vaporization temperature In addition, the Strubel device provides no mechanism for directing inhalation airflow relative to the portion of the fuel actively binning.
Finally, U.S. Pat. No. 6,089,857 to Matsuura is also directed to a flavor generation device that separates the combustion byproducts from the inhalation air. The Matsuura heat exchanger is a plurality of tubes arranged in the combustion area through which the inhalation air is drawn. This arrangement represents a high thermal mass, resulting in a delay in reaching the appropriate vaporizing temperature. This design also causes excessive heating of the device in the regions where the heat exchanger is attached to the device body and is expensive to fabricate.
Accordingly, it would be desirable to provide a vaporizing device for consuming botanical substances that uses the combustion of fuel as a heat source while maintaining separation between the combustion air and the inhalation air. It would also be desirable to provide a device that quickly and efficiently exchanges the combustion heat to the botanical substance while ensuring that the flow of inhalation air is directed past the hottest portion of the exchanger. Further, it would be desirable to provide a device that is readily and easily reusable. This invention satisfies these and other needs.